Telegraph keying device



Dec. 10, 1940. R. D. HUTCHENS 2,224,299

TELEGRAPH KEYING DEVICE Filed Feb. 24, 1939 INVENTOR. 247/270) D. Hl/Tfh'i/VJ ATTORNEY.

Patented Dec. 10, 1940 UNITED STATES PATENT OFFICE TELEGRAPH KEYING DEVICE of Delaware Application February 24, 1939, Serial No, 258,126

1 Claim.

This invention relates to keying devices for telegraph systems. In wire and radio telegraph systems, where traiiic is heavy enough to Warrant it, the signals are initiated by automatic devices operated by tapes which have been previously perforated to contain the signal of the communication to be transmitted. These devices are well known in the art and have been used commercially for many years.

It is common practice to send the signals over part, or all of, the circuit in the form of audio oscillations, or tones, broken up into the form of dots and dashes or other code to form the signal.

In prior art practice the tones have been produced by separate generators, usually of the vacuum tube type.

It is an object of this invention to produce these tones directly from the rotating parts of the tape transmitter drive mechanism.

Other objects will appear in the following description, reference being had to the drawing, in which:

Fig. 1 of the drawing is a conventional illustration of the invention.

Fig. 2 is a side view of the generator shown in Fig. 1.

Referring to the drawing, the automatic transmitting assembly is generally indicated at I. This consists of a tape transmitting mechanism 2 run by a motor 3 at various speeds that may be selected by gear shift arrangement cliagrammatically illustrated at 4. Perforated tape is automatically fed through the mecha-- nism 2 which operates pecker pins that actuate contact lever 5. The pecker pins and other parts of the tape transmitter are not illustrated as they are old and well known in the art.

In the prior art a separate tone generator is provided for placing tones on the control line to the radio transmitter. To obviate use of this separate tone source, I provide a generator in the automatic transmitter I. This consists of a toothed rotor 5' of magnetic material mounted 5 on the shaft 8 that drives the tape transmitter 2. Adjacent the teeth of this rotor is a magnetic core 1 spaced from the periphery of the rotor by a small air gap. Around the magnetic core I is wound coil 8, one terminal of which is connected to contact lever 5 and the other terminal of which is connected to control wire 9 leading to the radio transmitter. The other control wire 5 I0 is connected to the contact II.

In the operation of this system embodying my invention, the tape (not shown) will be perforated as usual from the message to be transmitted and as the shaft 6 rotates to feed this 10 tape through the transmitting mechanism 2, contact lever 5 will, in following the tape perforations, engage and disengage contact H and automatically connect and disconnect coil 8 with the radio transmitter. 15

The rotor 5', rotated by shaft 6, continuously varies the reluctance of the magnetic core I and therefore varies the flux through the coil 8. This produces a variable electromotive force in the coil which places a tone on the control lines 9 20 and [6 in accordance with the message perforated on the tape. Thus the automatic tape transmitter furnishes its own tone, and no separate oscillator for this purpose is required. The generator in my invention is a compact rugged 25 device. It is economical in operation because no vacuum tubes are required for generating the tone and, due to its construction, the generator requires practically no service for long periods of time. 30

Various modifications may be made in the form of the generator without departing from the spirit of the invention.

Having described my invention, what I claim In telegraph apparatus, a radio transmitter, a tape transmitting mechanism for producing mark and space signals, a shaft for operating said mechanism, a tone generator for producing a tone frequency in the mark signals consisting 40 of a toothed iron rotor on said shaft, a magnetic core adjacent the teeth of said rotor, a coil wound on said core, and a switch operated by the tape transmitting mechanism for connecting and disconnecting said coil to said radio transmitter.

RAYMOND D. HUTCHENS. 

